October 6, 2026, 5:57 pm | Read time: 5 minutes
Sore throat, cough, fatigue–with the onset of cold season, these symptoms are likely to become more common again. However, it’s not always just a regular respiratory infection. COVID-19 is also making its presence felt again. Currently, the variant XFG, also known as “Stratus” or “American Covid,” is in the spotlight. What symptoms can occur, what is behind the variant, and how dangerous it is.
What symptoms should you watch for?
Fever and chills, headaches and body aches, as well as a runny or stuffy nose, can occur alongside the already mentioned symptoms in a COVID-19 infection. Hoarseness is also associated with XFG.
In general, the symptoms are similar to those of other Omicron variants. However, there is a change compared to earlier phases of the pandemic: the once typical loss of smell and taste for COVID-19 is less common with the currently circulating variants.
Whether it’s COVID-19, the flu, or a cold causing the symptoms is hard to determine based on symptoms alone. A rapid COVID-19 test can provide a clue, but a negative result does not definitively rule out an infection. Therefore, it may be wise to repeat the test if symptoms persist.1
What is XFG (“Stratus”)?
XFG is a subvariant from the Omicron family. It emerged through a recombination of the two previous virus lines LF.7 and LP.8.1.2. Simply put, genetic material from two already existing lines combined.
XFG is not entirely new. The variant was first identified in January 2025 and has since spread worldwide. Besides “Stratus,” another name is circulating: “American Covid.” This is not an official designation but a media nickname related to the variant’s spread in the U.S. It does not imply that XFG originated there.2
XFG also plays a significant role in Europe now. The European Centre for Disease Prevention and Control (ECDC) lists the line as a “variant under observation.” According to the European health authority, XFG is now dominant in the EU and the European Economic Area.3
Why XFG is back in focus
New attention is currently being drawn by developments in England. According to the UK Health Security Agency (UKHSA), the positivity rate for COVID-19 tests in hospitals rose from 5.9 to 7.0 percent based on the latest September data. At the same time, the rate of hospital admissions related to COVID-19 increased by nearly 50 percent.4
The increase was particularly pronounced in London, where the rate of COVID-related hospital admissions rose by 79 percent. More than half of the positive tests detected a variant of XFG.
It’s not unusual for COVID-19 numbers to rise again at the start of the colder season. Immunity from previous infections and vaccinations can wane over time. Additionally, people spend more time indoors together in the fall, where respiratory viruses can spread more easily.
Despite the current increase, COVID-19 activity in the UK remains at a low level. Reported infections and hospital admissions are still significantly lower than in the comparable period last year.
How dangerous is “American Covid”?
So far, there is no evidence that XFG causes more severe illnesses than other currently circulating COVID-19 variants. The ECDC also does not currently indicate any evidence of increased disease severity for the line.
Severe COVID-19 cases are generally rarer today than in the early years of the pandemic. This is due to both the characteristics of the Omicron variants that have predominated since 2022 and the immunity built up in the population through vaccinations and previous infections.
However, COVID-19 can still be dangerous for at-risk groups. These include older adults, people with certain pre-existing conditions, and individuals with weakened immune systems. Current data from England also shows this: the highest rate of hospital admissions was recently recorded among people over 85 years old, rising from 7.08 to 12.43 per 100,000 people within a week.
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Who should get vaccinated against COVID-19?
For the 2026/27 season, vaccines adapted to the current virus developments will be used. The European Medicines Agency (EMA) recommends vaccines adapted to XFG for the season. The primary goal of vaccination is to protect against severe COVID-19 cases.
In Germany, the Standing Committee on Vaccination (STIKO) recommends an annual booster shot in late summer or early fall for people at increased risk of severe illness. This includes everyone aged 75 and older, as well as individuals from six months old with certain underlying conditions.5
The recommendation also applies to residents of care facilities and certain healthcare and nursing staff. There is still no general COVID-19 vaccination recommendation for healthy children and adolescents.
When should you see a doctor for COVID-19?
Most COVID-19 cases are now mild and can be managed at home. For fever, severe fatigue, and a pronounced feeling of illness, physical rest and adequate fluid intake are important.
It’s different with shortness of breath or increasing breathlessness. A persistently very rapid pulse, high fever lasting several days, bluish lips, or confusion should be medically evaluated. Older adults and people with pre-existing conditions should be particularly vigilant.